Binary classification: Difference between revisions

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(Created page with "==Introduction== Binary classification is a type of supervised machine learning task in which an algorithm is trained to classify an input into one of two possible categories, often represented as "positive" and "negative". To train its algorithm, it uses an existing dataset which contains inputs and their labels indicating which category each belongs in. Once trained, this algorithm can be applied to new inputs to predict their labels accurately. A binary classificatio...")
 
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==Introduction==
Binary classification is a type of machine learning problem in which the goal is to classify input data into two classes or categories. Often, these classes are labeled as positive (1) and negative(0), or true(1) and false(0) respectively.
Binary classification is a type of supervised machine learning task in which an algorithm is trained to classify an input into one of two possible categories, often represented as "positive" and "negative". To train its algorithm, it uses an existing dataset which contains inputs and their labels indicating which category each belongs in. Once trained, this algorithm can be applied to new inputs to predict their labels accurately.


A binary classification problem seeks to discover a function that accurately maps inputs to one of two possible categories. This boundary typically depicts this boundary as a decision boundary, dividing input space into two regions - one for each category - where points on one side are classified as belonging in one category while those on the other side fall under another classification.
Binary classification problems require input data in various forms, such as text, images, audio or numerical. The classification model learns from labeled training data where each data point is associated with a label indicating which class it belongs to.


Binary classification often relies on logistic regression. This algorithm employs a logistic function to model the likelihood that an input belongs to a certain category, with its output thresholded for final prediction accuracy.
Constructing a binary classification model typically involves selecting an appropriate algorithm, preprocessing input data, specifying features to be included in the model, training and assessing its performance. Popular algorithms used for binary classification include logistic regression, decision trees, random forests and support vector machines (SVM).


Support Vector Machines (SVMs) are another popular algorithm for binary classification. SVMs try to identify the optimal decision boundary that maximizes margin, or distance, between its closest points and those of each category. This produces a boundary which is more resilient to noise and outliers.
The performance of a binary classification model is typically assessed using metrics such as accuracy, precision, recall and F1 score. The appropriate evaluation metric depends on the specific problem at hand and how important correctly identifying each class is for success.


Random Forest is another ensemble learning algorithm that utilizes multiple decision trees to make predictions. It works by training multiple trees on different subsets of the training data, then averaging their predictions together for a final prediction.
Examples of binary classification problems include spam email detection, fraud detection, disease diagnosis and sentiment analysis.
 
==Explain Like I'm 5 (ELI5)==
Binary classification" is like when a teacher wants to know if you prefer apples or oranges more. They give both fruits and ask you to pick one, then mark it down on paper. The teacher does this with many other students so they can determine whether new students will prefer apples or oranges better.
 
An alternative way of looking at it is like sorting objects into two separate boxes, one labeled "yes" and the other labeled "no". The computer does this by taking pictures of the items and deciding which box it should put them in based on what it sees.